EZH2 and head and neck squamous cell carcinoma: The EZH2 inhibitor EPZ6438 has previously demonstrated strong inhibitory effects with a dramatic decrease in global H3K27me3 levels in head and neck squamous cell carcinoma (HNSCC) cells [52], and it has been FDA approved for the treatment of locally advanced or metastatic follicular lymphoma and epithelioid sarcoma [53,54].